module.exports = {
    events2: {},

    /**
     * @param {String} event
     * @param {Object} subscriber
     * @param {Function} handler
     */
    on: function (event, subscriber, handler) {
        function vip(){
             return handler.call(subscriber);
        }
        if (Object.keys(this.events2).indexOf(event) < 0) {
            this.events2[event] = [[], []];
        }
        this.events2[event][0].push(subscriber);
        this.events2[event][1].push(vip);
        return this;

    },

    /**
     * @param {String} event
     * @param {Object} subscriber
     */
    off: function (event, subscriber) {
        tt = this.events2[event][0].indexOf(subscriber);
        delete this.events2[event][0][tt];
        delete this.events2[event][1][tt];

        tt = this.events2[event][0].indexOf(subscriber);
        if (tt>-1) {
            delete this.events2[event][0][tt];
            delete this.events2[event][1][tt];
        }
        return this;
    },

    /**
     * @param {String} event
     */
    emit: function (event) {
        for (xx of this.events2[event][1]) {
            if (xx != undefined) {
                xx();
            }
        }
        return this;
    }
};